Anomalous orientation of poly(trimethylene oxy-2 trimethylene p-p' bibenzoate) as revealed by means of tensile tests

摘要

Poly(trimethylene oxy-2 methyl trimethylene p-p' bibenzoate) is a linear thermotrpic liquid crystal polymer that may or may not develop anomlous orientation depending on the applied strain rate. X-ray diffraction patterns show that macromolecular chains tend to align perpendicularly to the defomration direction for the solwest analysed strain rates and in parallel to the deformation direction for the highest rates. The study of the strain-stress curves reveals that plastic deformation of this polymer can be controlled by two different microscopic mechanisms whose relative contributions to the overall strain are rate dependent.